The present invention relates to a method of performing an operation on a workpiece and to a clamping body for use in performing an operation on a workpiece. Such an operation includes inspecting the workpiece and machining the workpiece.
In U.S. Pat. No. 4,070,120 there is disclosed a method of connecting two components with one another at their joint faces by an arrangement of positioning recesses and positioning elements in which the relative position of both components is defined in an exact predeterminable manner. This positioning accuracy is maintained even if the components are detached from one another and reconnected several times.
These and further advantages reside in the configuration of the positioning recesses, which converge in cross-section from the joint face, and on the converging configuration of the positioning elements, which thereby centre themselves within the positioning recesses. Also the material portions disposed in the neighbourhood of the relatively small contact region between positioning recess and positioning element are deformed in a controlled manner during the clamping together of the components.
The production, inspection and assembly of workpieces especially in the production of single parts and small batches is facilitated by preferably using the positioning means disclosed in the said patent.
A workpiece to be clamped-up in its turn is provided with corresponding positioning recesses, whereby the workpiece is positioned on a receiving surface of a clamping body by using associated positioning means. Production or inspection dimensions of the workpiece are then referred from the construction to a reference co-ordinate system which can be defined by the joint face and by the centre lines of at least two positioning means of the workpiece, which lie in the joint face.
If it is desired to undertake a machining operation or a measurement on the workpiece while using such a clamping body, then the difficulty arises that the positioning recesses serving as reference features are no longer detectable by measurement technique, since they were introduced from the joint face of the workpiece and are therefore no longer accessible after jointing.